I completely agree... the majority of the jokes felt forced and like they were trying way too hard. Hemsworth was the only one who pulled it off IMO, because he delivered his jokes in a rather subtle way and didn't try to make them any funnier than he had to, which made it feel more natural and unexpected. I usually find Wiig to be really funny, and I did chuckle at her a few times in this, but the others often ruined certain jokes she set up by trying to outdo her - that's one of things I can't stand about McCarthy... it's like she always sees it as a competition and has to be funnier by going OTT.
I'll more than likely give this a rewatch at some point anyway... I'm interested in seeing the extended cut now that
@Flloydo has mentioned it. I remember hating Bridesmaids for similar reasons when I first saw that back in 2011, then I rewatched it a few months back and enjoyed it a hell of a lot more! I honestly can't see that happening with Ghostbusters, but we'll see.